With the development of terminal technology, terminals have increasingly versatile functions. For example, a gradienter application (APP) may be installed on a terminal, to detect whether the terminal is at a horizontal level.
Conventionally, when an angle between the terminal and a horizontal plane is to be measured by the gradienter APP, the gradienter APP is initiated by the terminal, and a measurement interface provided by the gradienter APP is displayed on the terminal. For example, the measurement interface displays images showing liquid and a bubble in a container. During a movement of the terminal, the measurement interface displays that the bubble keeps moving with the terminal. The angle between the terminal and the horizontal plane is determined to be 0 if the bubble is displayed to be located in a middle of the container.